Method and mechanism for forming an overlapping carton closure



Dec. 13, 1955 P. E. FISCHER 2,726,497

METHOD AND MECHANISM FOR FORMING AN OVERLAPPING CARTON CLOSURE Filed Dec. 25, 1950 9 Sheets-Sheet l PAUL E. FISCHER E j NEAL I. PAULSEN IN VE/V TORSI- Dec. 13, 1955 P. E. FISCHER METHOD AND MECHANISM FOR FORMING AN OVERLAPPING CARTON CLOSURE Filed Dec. 23, 1950 9 Sheets-Sheet 2 /NVE/V7'0RS.'-

PAUL E. FISCHER NEAL l. PAULSEN 92 MM BY ATTORNEY FIG.2

D 1955 P. E. FISCHER METHOD AND MECHANISM FOR FQRMING AN OVERLAPPING CARTON CLOSURE 9 Sheets-Sheet 5 Filed Dec. 23, 1950 L V R R E M O H S TGL N h N F M4. N E I l L Mu BY% M "mm Dec. 13, 1955 P. E. FISCHER METHOD AND MECHANISM F FORMING AN OVERLAPPING CARTO LOSURE Filed Dec. 23, 1950 9 Sheets-Sheet 4 l/VVENTORS."

PAUL E. FISCHER NEAL l. PAULSEN HY Mflfi rromvgy Dec. 13, 1955 P. E. FISCHER 2,726,497

METHOD AND MECHANISM FOR FORMING AN OVERLAPPING CARTON CLOSURE Filed Dec. '23, 1950 9 Sheets-Sheet 5 fi FIG. ll

INVENTORSX- PAUL E. FISCHER NEAL l. PAULSEN BYM MZM mm Dec- 1 1955 P. E. FISCHER METHOD AND MECHANISM FOR FORMING AN OVERLAPPING CARTON CLOSURE Filed Dec.

9 Sheets-Sheet 6 IN VE N 70561- PAUL E. FISCHER NEAL l. PAULSEN fiYww 4770/?5) P. E. FISCHER METHOD AND MECHANISM FOR FORMING Dec. 13, 1955 AN OVERLAPPING CARTON CLOSURE 9 Sheets-Sheet '7 Filed Dec. 25, 1950 INVENTORS."

PAUL E. FISCHER NEAL l. PAULSEN By nrromvsr FISCHER M METHOD AND MECHANISM FOR FORMING Dec. 13, 1955 P. E.

AN OVERLAPPING CARTON CLOSURE 9 Sheets-Sheet 8 Filed Dec. 25, 1950 FIG. l6

INVENTORSF PAUL E. FISCHER NEAL I. PAULSEN ronfi y Dec. 13, 1955 P. E. FISCHER 2,726,497

METHOD AND MECHANISM FOR FORMING AN OVERLAPPING CARTON CLOSURE 9 Sheets-Sheet 9 Filed Dec. 23, 1950 FIG. 24

//VVENTOR$.'-

PAUL E. FISCHER NEAL l. PAULSEN 32s Z Z 4 B) ATTORNEY United States Patent METHOD AND MECHANISM FOR FORMING AN OVERLAPPING CARTON CLOSURE Paul E. Fischer and Neal I. Paulsen, Minneapolis, Minn.;

said Fischer assignor to General Mills, Inc., a corporation of Delaware, and said Panlsen assignor to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Application December 23, 1950, Serial No. 206,462

26 Claims. (Cl. 53-17) The present invention relates to improvements in packaging machinery Which closes and seals ,the top of a carton.

More specifically, the invention concerns an improved mechanism which will close and seal a carton constructed of soft non-rigid material such as is constructed of laminations of foil, tissue and thermoplastic adhesive. When sealing a carton such as this, great difiiculty is encountered in forming a top fold wherein the opposing top closure panels are folded into overlapping relationship in the plane of the carton top and no support is given the fold from inside the carton. The soft, light-weight foil is easily crumpled and torn and does not have the resilient properties which cause cartons of other material to spring back to shape. Also, the addition of heat softens the thermoplastic and further softens the material making folding more difficult.

An object of the invention is to provide an improved mechanism which will successfully fold a carton formed of soft, yieldable material with an overlapping closure and which will accomplish this at speeds suitable to adaptation in high speed automatic carton closing machinery.

A further object of the invention is to provide a mechanism which will simultaneously fold closure panels of a carton into overlapping relationship, heat the thermoplastic material on the facing surfaces of the closure panels and remove all wrinkles and irregularities in the closure material to form closure layers which will lie together smoothly for sealing without danger of having air leakage in the seal.

A further object of the invention is to provide an automatic machine which will fold the front and rear closure panels of a carton into overlapping relationship and the adjoining side closure panels into doubled triangular flaps and seal the carton by heating and cooling the thermoplastic adhesive between the contacting layers of a material.

Other objects and advantages will be apparent in the course of the following description and accompanying drawings in which:

Figure 1 is a side elevation of a mechanism for withdrawing the carton flap from the side of the carton and for elongating the carton mouth;

Fig. 2 is a perspective view of the entire operating station of Fig. 1;

Fig. 3 is a perspective view of the mechanism of Fig. 2, taken from the opposite side of the station;

Fig. 4 is an enlarged front elevation illustrating the mechanism for elongating the mouth of the carton;

Fig. 5 is a perspective view having parts broken away to illustrate the action of the mouth elongating mechanism;

Fig. 6 is a fragmentary plan view illustrating the anvil which lies beneath the carton flap;

Fig. 7 is a fragmentary side elevation illustrating the action of the mechanism for creasing the carton flap;

Fig. 8 is a perspective view of the mechanism of the "ice station for beginning the closing of the carton closure panels, having portions of the station removed to illustrate the condition of the carton before folding;

Fig. 9 is a side elevation of a mechanism of the station shown in Fig. 8;

Fig. 10 is an enlarged perspective of the mechanism which is mounted at the top of the tower for operating the folding shoe;

Fig. 11 is a sectional view taken along line 1111 of Fig. 10;

Fig. 12 is a perspective view of the station of Fig. 8 illustrating the action of the folding wedge;

Fig. 13 is a sectional view taken through the carton to illustrate the action of the wedge and folding shoe;

Fig. 14 is a perspective view illustrating the action of the wedge and shoe at a later point of progression than Fig. 13;

Fig. 15 is a sectional view taken through the carton, illustrating the wedge and shoe in the same position as Fig. 14;

Fig. 16 is a perspective view of the mechanism for sealing together the overlapping panels of the cartons;

Fig. 17 is a fragmentary front elevation having portions cut away to illustrate the action of the sealing shoe;

Fig. 18 is a fragmentary side elevation having portions cut away to illustrate the action of the sealing shoe;

Fig. 19 is a perspective view showing the details of the sealing shoe;

Fig. 20 is a plan view of the no-carton no-operation mechanism;

Fig. 21 is a perspective view of the adhesive cooling mechanism;

Fig. 22 is a fragmentary front elevation having portions broken away to illustrate the action of the cooling shoe on the carton;

Fig. 23 is a fragmentary front elevation illustrating the action of the carton holding blade;

Fig. 24 is a sideelevation illustrating the action of the cooling shoe and holding blade; and

Fig. 25 is an enlarged view showing the action of the clamping shoe.

In the preferred embodiment of the present invention, the carton is carried past a series of carton closing stations. At each station the carton is briefly halted and a closing operation performed thereon by suitable mechanism. The carton is shown carried by a holder having pockets'therein' which may be a turret of the general type shown in the co-pending application, Carton Closing Machine, Fischer, Hedin, Swanson and Wissman, Serial No. 206,464, filed December 23, 1950. It will be recognized from the drawings that the present mechanism could be incorporated into the machine shown in the above copending'application. The mechanism, however, is not to be limited to operation with a machine of that type and can be used with other suitable type automatic packaging machinery.

The carton is supported in a pocket 30 formed in a carrier turret 32, and rails 34 and 36, extending annularly around the peripheral face of the turret, hold the carton in the pocket. The turret is circular in shape and is intermittently rotated to carry the cartons past the closing stations by mechanism not shown. The rails 34 and 36 are supported on vertical posts 35 which are mounted on the annular supporting framework 37 which extends around the turret.

The carton, as may be best observed in Fig. 8, comprises an outer covering layer 38 and an inner liner 40 which is shorter than the outer layer of carton material. Portions of the inner liner and outer layer extend above the top face 41 of the turret 32, forming top closurev panels. The front top outer closure panel has received vertical slits along its side edges to form a top cover flap 42.

Inside of the cover flap 42 is the inner front closure panel 43. At the sides of the carton mouth are the side top closure panels 44 comprised of both the inner and outer layers of material. panel 43 is the rear closure panel 45, also comprised of the inner and outer layers of carton materiaL. It will be apparent from the description of the mechanism that the invention may be adapted .to closing either end of the carton.

The first operation of the machine is to separate'the cover flap 42 from the side of the carton and bend it downwardly into the plane of the carton top to prevent it from interfering with subsequent folding operations. The mechanism for folding the carton top is arranged to form. separate stations, the cartons being briefly halted at each station while the particular folding operation is accomplished, and then being moved to the next station.

The mechanism of the first closing station is shown in Figs. 1 through 7. In Figs. 2 and 3, a tower 46 is shown forthe purposes of supporting the folding elements which operate on the carton. The turret is indexed to move the carton to a position opposite this tower for the first folding operation. The tower is mounted on an annular framework 37 which surrounds the turret, and pillow blocks 48 on either side of the tower carry a constantly rotated cam shaft 50 which carries a positive action cam 52. A rocker arm 54 pivoted in the base of the tower has a follower 56 riding in the track of the cam. A tension spring 58 connected between the rocker arm and the tower takes up the lost motion between the follower and cam track. An upper rocker arm 60 is mounted at the top of the turret and an adjustable connecting rod 61 connects between the ends of the upper and lower arms. The inner end of the upper pivotal arm 60 is connected to a pair of adjustable push rods 62 (Fig. 4), the lower ends of which connect to arms of bell cranks 64and 68. These cranks are pivotally mounted ona cross head mounted for vertical reciprocation on a pair of vertical guide rods 72. A collar 74 held on the lower end of the guide rods by nuts 76 limits the downward movement of the cross head (Fig. 1).

Secured to the lower arms of hell cranks 64 and-68 is'a pair of flat' spreader shoes 78' which are flared downwardly to a wide base. A tension spring 80 connected between 'the'two lower arms holds the spreader shoe together. Alug'82 and a bell crank 68 strike an adjustable stop pin 84 to limit the pivotal movement of the cranks caused by the spring.

A bracket-86 on the side of the sliding block carries an adjustable push rod 38 which connects to a crank arm 99 mounted on a shaft 92 journaled in the tower wall. At theinner'end of this shaft is a second crank arm 94 pivotally carrying the upper end of the hook carrying member 96, the lower end of which is journaled to a guid ingtrank arm 98 pivotally mounted on the tower. A flap-grasping hook' 100 is secured to the carrying member to engage the flap and bend. it away from the mouth ofthe carton.

As the cross head descends from the solid to the dottedv line position of Fig. 1, the flap separating assembly is moved from the solid to the dotted line position, causing the hook to move through the path indicated by the arrows to draw the flap away from the carton mouth. The lower crank arm 98 is slightly longer than the upper crank arm. 94 and the arms are angularly displaced with respect to each other to give the carton engaging hook the :uniqueseparating movement shown by the drawings.

Thelocationof thehook in its normal raised position may Opposite the front closure be adjusted by altering the length of the adjustable push rod. 88. so that the hook will not interfere with the carton as it is carried opposite the tower by the carrying turret. After the flap is separated from the carton mouth,

mechanisms are employed to crease it along its line of attachment to the side wall to maintain it in an out-ofthe-way position for future folding operations. To this end, cam shaft 50 carries another cam 102 which is engaged by a follower 104 carried on a rocker arm 106 mounted at the base of the tower. A spring 108 between the rocker arm. and. tower operates the rocker arm. A

creasing arm 110 is pivotally mounted on the side of the tower and an adjustable push rod 112 connects the rocker arm to the creasing arm. At right angles to the end of the creasing arm is a creasing blade 114 extending parallel to the plane of the carton top. A pair of pins 116 protrudes from the tower side of the creasing blade to hold 'the flap in flattened condition when being creased, see Fig. 5.

To provide a base against which the flap may be creased, an anvil member 118, Figs. 2, 5, 6 and 7, is carried at the upper arm of a bell crank 120 pivoted at 122 on the tower. The upper edge 'of the rail is cut away at 123 in order that the anvil may be brought under the flap against the side of the carton. A rod 124 is secured to the rockerarm 54 and extends through a hole in a boss 125 on the bell crank arm. A compression spring 126 is positioned between a collar 127 on the end of the rod and the boss. As the arm 54 pivots, the anvil 118 will be moved against the side of the carton and the spring 126 will compress to compensate for over-travel of the pivotal arm 54. In operation, the bell crank is rocked topivot the anvil beneath the cover flap 42 whereupon the creasing blade slams down upon the flap to crease it. in the manner shown in Fig. 7.

It will be seen from the dotted lines of Fig. 6, representing the carton retaining'rail, that the rail must be curved to conform to the configuration of the periphery of the turret. Therefore, if the flap is bent down on the top of the rail without providing an anvil, it will be difficult to obtain a straight crease line at the base of the flap and generally the flap will'buckle and wrinkle or tear at its edges. The anvil is provided with a straight forward edge 128 which rests snugly against the side of the carton along the line of attachment and obtains a well defined straight crease in the flap.

Thesequence of operations at this station is in the following order. As the cross head 70 begins to descend through the action of the rocker arms, the flap-separating hook 100 first draws the closure flap 42 from the plane of the carton side wall to bend it back in the manne shown in Fig. 1. The anvil 118 then moves beneath the flap, and the blade 114 passes between the carton mouth and flap, creasing the flap along its line of attachment to the carton side wall. As the cross head 70 continues to descend, it strikes the stop collar 74. At this point, the continued movement of the rocker arms pushes the rods 62 downward, overcoming the tension of the spring 80 to begin pivotal movement of the bell cranks 64 and 63. The spreader shoes 73, moving apart, engagethe innerface of the side top closure panels 44, forcing them outwardly and creasing them over the upper side edges 132 of the turretpocket, as shown in Fig. 5.

Positioned on the surface of the turret on either side of the pocket are spring leaves 134 which, for purposes of. this application, serve-no other function than to form a flat upper surface upon which the side ears of the cartons may lie. The inner edges of these blades 132 form the corners of the turret pocket over which the side flaps are folded, as referred to in the preceding paragraph. The spreading of the side closure panels'44 elongates the mouth of the carton, drawing inwardly the front closure panel 43 and the rear closure panels 45. The shape of the shoes 78 is such that the upper section of the sidc-closure-panel becomes rounded over the narrower part of the shoe and the lower section, engaged by the-broader part ofthe shoe, is creased along its full width. Since the carton in the preferred form is of material such' as metallic foil, when the spreader shoes are withdrawn the mouth will retain this slightly elongated configuration. The purpose of forming the crease at the base of the side panels and for elongating the carton mouth will become apparent in the explanation of the folding function at the succeeding station.

As the rocker arms begin to pivot in the opposite direction, the bell cranks 64 and 68 pivot the spreader shoes together, and when the lug 82 strikes the stop 84, the cross head 70 begins to ascend returning the elements of the folding mechanisms to normal position. At that point the carton-carrying turret indexes the carton to the next station where it will be opposite the tower and the folding elements shown in Figs. 8 through 15. A curved rail 135 cams the flap 42 downward maintaining it in an out-of-the-way position for subsequent folding operations.

The function of this station is to begin the operation on the closure panels which will place them in a position where the front and rear panels may be folded into overlapping relationship and the side closure panels are placed in a position where they may be forced together to form double thickness laminated ears which extend outwardly beyond the carton side walls in the plane of the carton top. The mechanism of the station also functions to heat the thermoplastic adhesive preparatory to the sealing of the closure panels in the prescribed relationship.

To accomplish these functions a uniquely shaped spade or Wedge element 140 has been provided. The spade is wedge-shaped in profile, having an upper face 142 and a lower face 144 tapering to a front edge 146, which is substantially the width of the carton. As viewed from the top, the wedge has winged sides flaring outwardly from the front edge. The wing-shaped sides 148 are rounded, the radius of curvature increasing from the front edge to the rear.

A series of heating elements 150 mounted in the wedge body from the rear, Fig. 15, supply heat to the wedge and are held in their position by setscrews 152. Electrical leads 154 connected to a suitable source of electricity supply the heating elements. The wedge is carried on a vertical rocker member 156 carried on a pivotal shaft 157 in the base of the tower 158, the tower again being mounted on the annular frame 37. A mounting plate 160 is secured to the wedge and is carried on the top of the pivotal rocker member 156 and separated therefrom by an insulating layer 162 (Fig. 12). To give movement to the pivotal rocker member 156, an arm 164 (Fig. 9) is secured to the shaft 157 and has a follower 166 which rides in the track of a cam 168 carried on the cam shaft 170 which is journaled in pillow blocks 172 mounted on the tower.

As the cam rotates, the pivotal rocker member 156 carries the heated wedge into the mouth of the carton. The forward edge 146 of the wedge first engages the front top closure panel 43 of the carton, forcing it over the carton contents to a position where the lower face 144 is positioned in the plane of the carton top in contact with the front inner closure panel of the carton (see Figs. 12 and 13). Since the side closure panels 44 remain spread slightly from the elongation action of the previous folding station, the front edge of the wedge easily moves between them without danger of wrinkling the corners at the joinder of the front and side closure panels. The side closure panels 44, being positioned slightly outwardly, begin to be forced further outwardly by the wedging action of the side wings 148 of the entering wedge. A portion of the inner layer of the side closure panel is doubled upon itself, and the side closure panel is folded outwardly, curved along a diagonal line 174 extending from the upper front corner of the panel to the lower rear corner as shown in Fig. 12. The forcing of the side closure panels outwardly draws the rear closure panels inwardly, pulling them against the upper face 142 of the wedge. The wedging action against the side closure panels also draws the entire mouth of the carton taut to remove any wrinkles or disfigurations which may have inadvertently occurred to the material of the closure panels, thus presenting a smooth material for future folding which is not susceptible to forming pockets to permit air leakage.

The wedge being heated also softens the thermoplastic coating which is present on the inner faces 176 of the outer layer of the closure panels and present on the outer face 177 of the inner layer of the closure panels. The wedge is held in the fully inserted position illustrated in Fig. 12 for a time adequate to completely soften the thermoplastic adhesive.

It will be noted that the heat is applied to the closure panels on the faces which will engage each other in sealed relationship, thereby insuring that all the adhesive will become softened. This is highly advantageous over a method of heating where the heat is applied to the noncoated sides of the carton material and the heat must be conducted through the material to soften the adhesive. It will be seen that in such an instance, due to the variance in the number of layers of material through which the heat must penetrate, uniform softening of the adhesive is impossible.

In order to insure that the rear closure panels 45 of the carton will be in engagement with the rear face 142 of the heated wedge, a shoe 178 presses the rear panel against the face of the wedge in a manner shown in Figs. '14 and 15. The mechanism for operating this shoe is carried on the tower (Figs. 9 and 10). Mounted on a cross pin 180 on the top of the tower is a pivotal yoke 182 constructed of side members 184 interconnected by rigid connecting bars 186. On the inner end of these side members 184 are secured elements 188 having arcuately-shaped elongated slots 190. Slidably cradled in these slots are arcuately-shaped elongated bosses 192 which are secured to the side of projecting carrying arms 194 extending from the back of the pressing shoe 178. These bosses are non-rotatable in the slots and guide the path of action of the shoe after it has been lowered to a position where the forward edge 196 of the shoe lies substantially coincident with the rear edge of the carton at the line of attachment between the rear closure panels and their supporting side walls. Pins 202 are threaded into the projecting arms 194 and extend laterally outwardly through the elongated bosses to carry a block 204 which is journaled thereon. Details of this construction are shown in Fig. 11. Cotter keys 206 hold the blocks on the pins. A pair of pivotal arms 208 are mounted on the cross pins 180 outside the yoke members 184, and the sliding block 204 is slidably held between the fingers 210 of the bifurcated end of the arms 208. Tension springs 212 between the outer ends of the arms 208 and the yoke member 182 pull these outer ends together to hold the elongated boss 192 into the topmost portion of the slot 190. To rock this complete assembly and operate the shoe, an adjustable rod 214 pivotally connects to one of the arms 268, the other end being connected to a rocker arm 216 pivotally mounted on the tower. The inner end of the rocker arm carries a follower 218 which engages a cam 220 carried on the cam shaft 170. A tension spring 222 between the rocker arm and tower holds the follower against the cam to operate the arm as the cam rotates.

As the machine operates, and while the heated wedge is entering the carton mouth, the rocker arm 216 is pivoting the shoe assembly at the top of the tower counterclockwise, as shown in the drawings. As the shoe reaches the position in Fig. 13, stop lugs 224 on the yoke strike adjustable stop pins 226 on the tower terminating the pivotal movement of the yoke. Continual movement of the rocker arm overcomes the tension of the spring 212, causing the elongated boss 192 to begin moving downward in the slot 190. The slot is so shaped that at that position it will have its radial center at the rear edge 200 of the carton and therefore the shoe will swing inwardly, pivoting about its edge 196 to force the rear amen-97* closure panel 45 of the carton against the upper face 1423of theclosing shoe, as illustratedin Figs..l'4 and. 15;.

A's'theboss moves downward in this slot, the sliding block 204 slides between the fingers 210 of the arms 208. When the shoe has pressed thev rear closure panels of .the carton against the heated wedge for a period'of'time sufficient for the: heat; to soften the thermoplastic adhesive, the assembly returns to normal position. It is to be. noted that the shoe'operating assembly is carried outside of the turret so as not to interfere withthe movement thereof. The unique linkage employed permits positioning of the operating mechanism outside the. turret although the folding shoe is required to approach the carton from the oppositeside from inside. the turret. As the folding shoeandshaped wedge recede from the carton top, the carton willimmediately be transported to the next folding station for sealing the facing surfaces together.

The sealing. station is shown in Figs. 16 through 20. The-turret brings the carton to a stop opposite. the tower 230; which is. mounted on the annular frame 37. On either side of the tower, pillow blocks. 232 carry the cam shaft 234 which is rotated with the cam shafts journaled at'the base of the other towers by virtue of being connected thereto by bevel gear 236. A rocker arm 238 has a follower'240 which rides on the. cam 242. on the cam shaft. At-the top of the tower. a second rocker arm 244 is pivotally mounted and is connected by an adjustable connecting rod 246 to the lower rocker arm. A tension spring 248 connected between the lower rocker arm and a bracket 250 mounted on the frame holds the follower against the cam and pivots the arms as the cam rotates. The inner end of the rocker arm 244 is connected to a cross head 252 which slides on verticalguide bars 254. A pin 256 extending across a. recess 258 in the cross head is positionedin an elongated slot 260 in the rocker arm. An extension 262 secured to the cross head carries the heated sealing plate 264, shown in detail in Fig. 19.

The heated plate has a fiat lower surface 266 and has heating elements 268 extending into the plate from either end. Leads 270 connect between the heating elements and a connector box 272'carried on the cross head and a flexible lead 274 connects from the box to a suitable source of electricity.

The mouth of the carton is in elongated condition and the adhesive heated and softened from the previous station. The heating shoe of the present station forces the elongated mouth together to cause the facingsurfaces of the closure panels into adhering contact by forcing the rear closure panel 45 into overlapping contact with the front closure panel43and creasing the side closure panels 44 into double laminated ears. The sealing plate is lowered on the top of the carton, forcing the closure panels into a flattened position as shown in Figs. 17 and 18.

The thermoplastic adhesive has remained heated on the surfaces of the closure panels from the previous station and the sealing plate 264 is heated to prevent solidifying of the adhesive at this station from contact with a cold surface. The sealing plate, after forcing the closure panels to folded position, islifted from the carton and the carton is indexed to the next succeeding stationwhich performs the function of cooling and solidifying the thermoplastic adhesive.

The present station is providedwith a no-carton, nooperation mechanism shown in detail in Figs. 16 and 20. A vertical shaft 278 is journaled in brackets 280 and 282 on the inside of thetower. and carries an arm 284 which has a roller 286 on its outer end which rides against the peripheral-surface of the rotating turret. When no carton is present. in. the pocket, the spring 288 connected be tween the tower. and..the.. arm pivots the arm into. the

empty pocket, moving the stop lug 290 on the. upper end of' the rod beneath a bracket 292 secured tothe upper rocker arm to prevent the tension spring248 from pivoting said arm. A stop finger 294' carried on the lower bracket- 2.80 prevents excess rotation ofthe arm 28.4:

Normallygwhen a,carton is present in thepocket'ofithe turret;.the arm 284 will remain in the position shown in Fig. 20 and the lug 29.0'will not interfere with the pivotal.

operation of the rocker arm 244..

The turret next indexes the carton into thecooling station, shown in Figs. 21 through 24, opposite the tower 300. The tower is mounted on the annular framework. On.

the inner end of this rocker arm, a follower 304 rides on. a earn 306 carried on cam shaft 3.08which receivesa.

3.7 and carries arpivotal. rocker. arm 302.111 itsbase.

constant rotation in unisonwith the other cam shafts by means of bevel gear 310. Pillow blocks 312 on either. The.

31.6 pivotally mounted in the upper end of the tower. A-

tension spring 318 between the lower rocker arm and a bracket 320 on the tower givespivotal movement to the, rocker arms as the cam rotates. The inner end'of the,

upper rocker arm 316 is bifurcated and pinned to an in:

vertedT. bar 322, the upper end of the bar being pinned- 328. Heat is removed'from the cooling block by-rneans of constantly circulating water fed in throughflexible supply tube 330 and returned by flexible tube 332. The. tubes are connected to supply and return pipes 334 and. 336 by connector blocks 338 and 340 mounted on the side of the tower.

Brackets 342 are secured on the side of the cooling block and carry resilient clamping elements 344 made preferably of rubber. The lower surface of these clamping elements extends below the lower surface of the cooling block in normal condition, as shown in Fig. 21.

Inoperation, the rocker arms lower the cooling block down upon the topof the carton and the clamping elements 344 first engage the lateral triangular flaps or ears 276, clamping them tightly against the upper fiat surface 346 of the spring leaf members 134 on top of the turret. The continued lowering of the cooling block compresses the clamping elements 344, lowering the crowned surface 328 and pressing it down upon the rear closure panels 45, forcing them against the underlying front closure panel 43, as shown in Fig. 22. The lower edge of the coolingblock is rabbeted at 347 to prevent pinching the carton againstthe top edge of the carton pocket. As these panels are depressed below the plane of the carton top;. they become taut and the underlying front closure panel;

out from between the seams and contacts the cooling block, causing the carton to adhere thereto. To prevent the block, when lifted, from withdrawing the carton from the. pocket of the turret, the machine is provided with a restraining blade 348, shown in detail in Fig. 23.

This blade is carried on a resilient holder arm 350 which.

holds the blade tightly against the carton top. The holder arm is suitably secured to the turret at a point notshown. The blade has a rounded leading edge 352 which causes it to ride up over the carton top as the turret indexes the; carton therebeneath. Therefore, when the cooling block.

is raised, the lower edge 354 of the restraining-blade'will hold the carton in the turret pocket, causing the sealing head to break away from the carton top. The.positionof these elements is shown in detail in Fig. 24.

Thus the machine has formed a smooth integral airtight overlapped type carton closure. The novel heated wedge has removed all wrinkles from the closure panels and has, in the same operation, begun the closure fold and has uniformly heated the thermoplastic adhesive to a condition where the closure may be completed by merely forcing the surface together and cooling the adhesive. The machine, combining the functions in unit operations, is susceptible to high-speed closing operation.

, It is to be understood that the use of the machine is not to be restricted to closing the type of carton shown, but various aspects of the invention may be easily adapted to the use of different types of cartons while employing the principles of the present invention.

Generally, the carton which has been sealed by the present machine will be completed by other suitable machinery which folds the lateral triangular flaps over the carton top and seals the top cover flap over the carton end to present a smooth completed closure.

While the invention is susceptible of various modifications and alternative constructions, we have shown in the drawings and have described in detail the preferred embodiment. However, it is to be understood that we do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

We claim as our invention:

1. In a mechanism for closing the top of a carton, a member insertable into the container mouth having tapered sides which engage opposing side panels of the carton which are to form part of the closure forcing them outwardly thereby drawing the front and rear closure panels toward each other in overlapping relationship, and means to seal the overlapping front and rear closure panels in overlapped relationship.

2. In a mechanism for closing the top of a carton, a member having sides which enter the carton mouth and engage the side panels of the carton top closure and which are tapered outwardly and rounded, the radius of the curvature increasing away from the portion first to enter the carton, means to insert said member into the carton forcing the side closure panels of the carton top outwardly and drawing the front and back closure panels toward each other in an overlapping relationship, and means to seal said front and back closure panels in overlapping relationship.

3. In a mechanism for closing a. container top, a wedge-shaped member insertable into the container top having sides which enter the carton mouth and engage the side panels of the carton top closure and which taper outwardly to force the side closure panels outwardly beyond the plane of the container side walls and which have a flat undersurface which lies in the plane of the container top when said shaped member is fully inserted, the undersurface engaging the outer face of the front closure panel of the carton, and means for sealing the rear closure panel to the front closure panel.

4. A mechanism for sealing a container including a shaped mouth forming member insertable into the mouth of the carton having a leading edge and top and bottom surfaces joining at an acute angle and having rounded side edges tapered outwardly from said edge, means to insert said member into the mouth of the container to elongate the mouth thereof, to force the side closure panels outwardly beyond .the carton side wall, and to force the front and rear panels into overlapping relationship, and means for sealing said front and rear panels in overlapping relationship. 1

5. Amechanism for closing the top of a carton including a wedge member adapted for insertion into the mouth of the carton and forcing the front closure panel of the carton over the carton body, the sides of said wedge member engaging the side closure panels and forcing the panels outwardly from the carton. top into overlap=- ping triangular ears upon entry into the carton mouth, thereby drawing the rear closure panel over the front panel into overlapping relationship, and means for joining said overlapped front and rear panels into integral sealed relationship to close the carton.

6. A mechanism for closing the top of a carton having thermoplastic adhesive on the closure panels comprising a shaped heated mandrel movable into the mouth of the carton to engage and fold the front panel over the carton, means to cause the rear panel to contact the surface of the heated mandrel, the mandrel contacting only the surfaces which will be in facing relationship when the panels are folded to directly heat the thermoplastic adhesive on those surfaces, and means to fold the rear closure panel over the front and to press the closure panels into overlapping relationship to cause adherence of the closure panels to seal the carton.

7. A mechanism for closing the top of a carton having a layer of thermoplastic adhesive on the closure panels comprising a heated wedge having top and bottom surfaces which taper to a thicker portion from the leading edge and having lateral projections tapering outwardly from said edge and extending wider than the carton top, said wedge insertable with the leading edge foremost into the mouth of the carton to force the front closing panel inward over the carton and to force the side closing panels outwardly drawing the front and rear closure panels against the wedge surfaces to heat the thermoplastic adhesive thereon, and means to press the heat-softened adhesive-coated closure panels together to seal the carton.

8. A mechanism for closing the top of a carton comprising means for supporting the side walls of the carton, a closing element movable over the top of the carton to fold the closure elements and having a forward edge which moves against the line of attachment of the rear closure panel to the rear wall, said closing element having fixed lateral wings shaped to taper outwardly to portions wider than the carton top which fold the side closure elements outwardly over the side wall to draw the rear closure element over the carton top creasing it against said forward edge.

9. A mechanism for closing the top of a carton com-- contacting one closure panel forcing it over the carton and the sides of the member subsequently forcing the adjoining closure panels outwardly from the plane of their supporting side walls to draw the remaining closure panel over the carton top.

10. A mechanism for closing a carton comprising in combination a wedge-shaped member having sides tapering outwardly from a forward edge to a width wider than the carton top and movable toward the carton in a path of motion forming an acute angle with the plane of the carton top, means for moving the wedge-shaped member in said path, said forward edge of the wedge member engaging the front closure panel and side panels and forcing thefront panel over the carton and the sides of;

the member forcing the side closure panels outwardly beyond the planes of the side walls thereby drawing the rear closure panel over the carton top and stretching the front closure panel in the plane of the carton top.

11. A mechanism for sealing a carton comprising a wedge-shaped folding element having sides which taper outwardly to a width wider than the carton top, and a pivotally mounted means carrying said wedge and adapted to move it in an are into the top of the carton to force. the forward closure panel over the carton and to wedge the side closure panels of the carton outwardly.

12. A mechanism for closing the top of a carton comprising a wedge-shaped folding member having sides which taper outwardly to a width wider than the cartontop, means movingthe folding member into the carton mouth, said member forcing a first closure panel over the-carton top and .wedging the adjoining closure panels outwardly beyond the side walls, a folding shoe, and means formoving the shoe towardthe folding member forcing the closure panel opposite the one first forced over the carton against said folding member.

13. A mechanism for closing the top of a carton having a coating of thermoplastic adhesive comprising a heated folding member having an upper and lower surface with wedge-shaped extensions on either side, means to move the member against top closure panels of the carton, the lower-surface forcing the front-closure. panel over thettop of the cartons and the extensions forcing the side panels out beyond the planes of the side Walls, means to force the" rear closure panel against the upper surface of the member, saidsurfaces and extensions transmitting heat to the panels to soften the thermoplastic adhesive, and means to seal the' front closure panel'to the overlapping rear closure panel;

14. A machine for closing a carton comprising a folding memb'er movable to fold a first closure panel of the carton over the carton top, a second folding member first movable to folding position through an arcuate path having-its radial center-on the side of the package of said first panel and subsequently movable through an arc having-its centeron'the opposite side of the package to fold a closure panel opposite said first panel inwardly over the-package.

15; A machine for closing a carton having closure elements with a coating of thermoplastic adhesive thereon comprising a heated folding member movable against theclosure elements of the carton through an are having its center at the front side of the carton to engage and fold a frontclosure element over the top of the carton softening thethermoplasic adhesive thereon, a second presser member movable through an are having its center-on the front'side of the carton to a folding position and-then pivotable about an are having its center on the rear sideof the carton to fold the rear closure element against said-heated member to cause the thermoplastic adhesive on the closure element to be softened, and means for sealing the rear'closure element to the front closure element.

l6.- A mechanism for closing a continer having a flap formed from one closure panel by vertical cuts extending alongthe side of the fiap comprising means to pull the carton flap from the carton mouth down to the plane of the carton top, a wedge-shaped folding. element insertable intothe carton mouth through the opening. vacated bythefiap wedgingthe closure elements adjacent the flap I outwardly drawing the rearclosure panel over the carton top, and means to fold the rear panel into the plane of the catrton top.

17. A mechanism for closing a carton having a flap 4 formed from a closure panel by slits extending down.- ward along eachside comprising means for drawing the flap from the plane of the side wall to the plane of the top of the-carton, means for holding the flap in the plane of the carton top to give access to the carton mouth, a

wedge-shaped folding elementmovable over the flap to spread the side closure panels outwardly to draw the closure panel positioned opposite the flap over the foldingelement, and means to'fold'said opposite panel into the plane of the carton top.

18. A mechanism for folding a carton having a liner anda covering layer each having closure elements extending above the plane of the carton top and having, a flap cut in the front of the carton from a closure element of the covering layer, the mechanism comprisingmeans tenfold; the flap outwardly into the'plane'of the carton top, a shapedwedgeimovable over thecarton'through the space -tormerly occup ediby the closure flap forcing the front closure element of the-liner over thecarton andtforcing the side closurepanels of the liner-and coveringlayer outwardly over the carton side walls thereby drawing 12. the rear closure panels over the carton, and means to fold the rear closure elements over the carton.

19. A mechanism for closing the top of a carton comprising means to crease the sides of the carton at the joinder of the side top closure elements and side walls, a wedge-shaped folding element having spreadersidestapercd outwardly from the forward edge, means for insert-.

ing the folding element against the front closure element:

of the carton'to force it inwardly, the spreader sides forc ing the side closure elements outwardly to draw the rear closure panel over the carton body, and means for folding the rear closure element to the plane of the carton top.

20. A mechanism for closing cartons comprising in combination means for supporting the bodyof the carton, means for laterally elongating the mouth of the carton creasing the sides along the line of attachment of'the closure elements to the side walls, a spreading closure wedge movable against the closure panels to fold the side closure panels outwardly and draw the rear closure panel over the carton, and means to fold the rear closure panel into the plane of the carton top.

21. A machine for closing a carton having closure panels comprising in combination means to supportthe carton side walls, spreader shoes to elongate theimouth of the carton and provide a crease joinder line between the side closure panels and side walls, and a folding member tapering with upper and lower fiat surfaces to a forward creasing edge and having rounded tapered sides leading back from each end of the said creasingedge, means for moving the folding member into the carton against the closure panels to a position where the'lower face lies in the plane of the carton top and the creasing edge lies substantially along the line of attachment of a closurepanel' and a side wall, said folding member folding the front closure panel over the carton top to' where it lies against said lower fiat surface and folding the side panels outwardly and drawing the rear panel inwardly creasing it over said creasingedge;

22; A mechanism for closing the top of a carton comprising a folding member having tapered sides, means to actuate the member moving it against the closure panel of the carton to force a first closure panel over the top of the carton, the tapered sides forcing he adjoiningpanels outwardly drawing the remaining panel over the carton,

and a presser member forcing said remaining panel into overlapping relationship with 'said' first panel and creasing said adjoining panels into triangular laminated ears extending outwardly from the carton in the plane of the top.

23. A mechanism for closing a carton having closure elements coated with thermoplastic adhesive comprising in combination a heated closing wedge having upper and lower surfaces terminating in a creasing edge and having rounded side surfaces flaring outwardly, means for moving the wedge over the carton top forcing the forward, closure panel inwardly over the carton top and creasing. the side closure panel's outwardly to draw the rearclosure panel against the wedge, said wedge transmitting heat to the closure elements to soften the adhesive thereon, means to withdraw the wedge, and means movinggdownwardly on the top of the carton to force the CIOSIII'CIPEIHCIS into laminated overlapping relationship pressing the thermoplastic coated surfaces together to seal the carton.

24. The method of heat sealing a carton having top, closure panels coated with a thermoplastic which comprises forcing the front closure'panel' over the top of the carton while forcing the side wallsoutwardly to draw the front panel tight in theplane of the carton top and drawing the rear panel over the carton, applying'heat'to'allsur faces of the closurepanel'sin facing relationship, and

forcing said surfaces together to cause adherence of thethermoplasticthereby sealingthe carton;

25. The method: of closing and heat sealing a carton having a' thermoplastic coating on the closurepanelstwhichii comprises creasing the side walls along the line of attach- 13 ment between the walls and closure panels, forcing the front closure panel inwardly over the carton, forcing the side panels outwardly drawing the rear panel over the carton, subjecting the coating on the closure panels to heat on the surface of the panel which will be attached to a facing surface, and forcing the closure panels together forming an overlapping closure.

26. The method of closing and sealing a carton having a thermoplastic coating on the closure elements which comprises forcing opposing front and rear closure elements toward overlapping relationship and forcing the intermediate closure elements which are connected to the front and rear elements outwardly of the carton into triangular elements, applying heat to the front and rear closure elements on the surfaces in facing relationship and 15 References Cited in the file of this patent UNITED STATES PATENTS 1,818,497 Milmoe Aug. 11, 1931 1,868,686 Belcher July 26, 1932 1,989,471 Belcher Jan. 29, 1935 2,118,488 Butler May 24, 1938 2,169,311 Widell May 15, 1939 FOREIGN PATENTS 201,559 Great Britain Apr. 10, 1924 580,273 Germany July 12, 1932 

